Typewriting machine



Nov. 27, 1928. 1,693,533

B. c. STICKNEY TYPEWRIT I NG MACHINE Filed Sept. 21, 1926 FFy/l W llfi'riilllll III, I

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This invention relates to sound-deadening platens for typewriting machines. One of its objects is to provide a simple and menpensive uiet platen, which wil substantially absorb t e vlbration set up by the typeblows, while at the same time presentin a hard surface to the types, thereby rendering the machine especially adapted for manifolding. I

The advantage of using lead or plastic material for constructing a platen so as to prevent vibration thereof, is set forth in in pending a plication No. 10,768, filed May 3, 1924. o'wever, a platen made of this material is weak, and is liable to bend when made of eat length.

Accor 'ng to one feature of this invention, means are provided for stifienini the platen, to prevent distortion thereof. ccording to another feature, the outer surface of the platen is made hard to facilitate manifolding. To these ends, there is provided a steel tubing, which is surrounded with a shell of soft rubber, which shell serves as a backing for a lead tubing driven thereon. The lead tubing is.- -shorter than the steel tubing to allow room for rubber collars at each end, which are cemented-to the steel tubing and to the ends of the lead tubing. This forms the core of the platen, which is cylindrical and of uniform diameter throughout its length. A thin sheet of rubber is wound, under tension, over this core and serves as a backing for a hard sheath of celluloid which is cemented over the rubber. The hard sheath prevents local'yielding of the platen when struck by the types.

The thin sheet of stretchable rubber tightly wound around the lead tube resents a highly elastic backing for the cellu oid, because ofthe high tension under which itis wound. However, the local yield to the types is much reduced as compared with the untensioned rubber usually provided for platen-jackets.

The outer surface is preferably made of celluloid, which is excellent for manifolding. It has been found that a platen made in this manner is excellent for clearness of .printin because of the outer hard layer, while tfieintervenin layer of soft material between the celluloid and the lead gives the further efiect of quietness. The lead being vibration of the of e stri of an inherent plastic nature prevents bodily Flatten, wh ch further rethe type-blows. The inertia of the heavy platen resulting from the weight of the lead assists also in preventing bodily vibration of theplaten and further conduces to uiet operation.

The finis ed cylinder is resiliently mounted on an axle by means of intervening soft rubber collars, which are cemented to the steel tubing and over end caps which are fast tov the axle. The laten may be finished to the exact diameter y grindin Other features and advantages will hereinafter appear. v

In the'accompanying drawin Figure l is a crosssectional view, showing the structure of the platen. i

Figure 2 is a diagrammatic view, showing the manner of constructing the platen.

Figure 3 is a cross-sectional view through line 3-3ot Figure 1. v

A steel tube 10 serves as a base upon which the platen is built. This tube may be about one inch, outside diameter, and one-sixteenth in wall-thickness, th length of the platen being equal to thelength of the tube. A rubber shell 11 is driven over the steel tube and serves as a backing for a; lead tube 12, which is in turn driven over the rubber shell. The rubber shell is preferably made of soft Para rubber, and may be about one-quarter of an inch thick. The rubber shell is driven over the steel tube, and is cemented, or otherwise secured to the tube. The lead tube'may be a piece of straightened commercial lead pipe such as is used for lumbingj. work. Both the rubber shell and the le tube are held in place by means of end, collars 13, which are made of soft rubber. The outside diameter of side diameter of the lead tube.

As has been statedin my priorv application, the lead is efiective to prevent vibration of the platen, because of its wei' ht. Due to its plastic nature, however, lea is liable to be pitted by the typeblows. To prevent this, it'is proposed' to d over the lead a thin sheet of stretched rubber 1d, and then wind over 15. The celluloid me be wound in the form wide, which is cemented one inch to the ru bar. The e vial thielmess of duces the noise 0 these collars is equal to the outthe rubber a thin sheet of celluloid celluloid may be one thirty-second of an inch, Which is subsequentl reduced to one sixty-"fourth of an inch w on the platen is trned by grinding.

In order to provide a resilient connection between this built-up core and its supportin axle 16, there is provided a pair of on plates 17, which are fast to the axle by means of screws 18, and a pair cl rubber collars 19, which may be cemented to the inner surface of the steel tube 10 and to the end plates. Variations may be resorted to Within the scope of the invention, and portions of: the improvements me be used without others.

Having thus 'escribed my invention, 1 claim:

1. A platen for a typewriting machine, including, in combination, a metal tube, a soft rubber shell for cncasinu said tube, a lead tube overlying said she l, a thin sheet of tightly-Wound rubber, and a sheath ol tightly wound celluloid.

2. A platen for a typewriting machine, including, in combination, a metal tube, a soft rubber shell :ior encasing said tube, a lead tube overlying said shell, a tightlyavound covering of hard material ilor protecting said lead tube a ainst the type-blows, and a thin layer oil salt material between the covering and the lead tube. s

3. A plat-en for a typewriting machine, includinc, in combination, an axle, a metal tube, collars of resilient material ior carryinc; said tube, said collars being carried by said ads, and alternate layers of resilient and plastic material, said layers including a soft rubber shell overlyiru the metal tube, a tube or plastic material over saidrubber shell, thin layer cl rubber over said plastic dill till

material, and celluloid.

.th platen for a typevvriting machine, including artist-a1 tube, and llanges l ast upon a platen-aria, rubber collars carried by flanges for resiliently supporting said tube, a rubber shell secured to the tube, a lead tube over said shell, the latter and the lead tube being shorter than the metal tube, a pair oil rubber collars secured to the metal tube at the endsthereoff, the inner surface of the collars being cemented to the ends oi the thin outermost sheath oi menace fforming a cylindrical body of uniform diameter, a sheath of protecting material to .present a hard local non-yielding surface to the types, and a backing-bf soft material for said sheath. v

5. A platen for a typewriting machine, including a metal tube, end flanges fast upon a platen-axle, rubber collars carried by said flanges for resiliently supporting said tube, a rubber shell secured to the tube, a lead tube over said shell, the latter and the lead tube being shorter than the metal tube, a pair of rubber collars secured to the metal tube at the ends thereof, the inner surface of the collars being coincided to the ends of the rubber shell and to the lead tube, the Whole forming a cylindrical body of uniform diameter, a tightly-Wound layer of thin rubber over and cylindrical surface, and a sheath of celluloid tightly around over said layer of thin rubber. I

6. A cylindrical platen for a typeivriting machine, including a reinforced lead core and a thin stiff covering for said core, the latter servingas a means for protecting the lead core against ty e-bloW identations, said still covering being acked by an intervening thin layer of flexible material 7. A cylindrical platen tor a typewriting machine, including a reinforced lead core and a'thin stifi covering for said core, the latter serving as a means for protecting the lead core against type-blow indentations, said still covering being backed by an intervening thin layer of Horrible material, and means for cushioning said core upon a sun- L. l 1 porting platennale.

BURNl-lhl d C STICHIEYQ till 

